Calculation of Complex Impedance Coating for the Back Scattering Minimization

2007 ◽  
Author(s):  
Boris Z. Katsenelenbaum ◽  
Nikolai N. Voitovich
Keyword(s):  
Complex Impedance ◽  
Back Scattering

Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Author(s):  
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Single Phase ◽  
Sol Gel ◽  
Complex Impedance ◽  
Transmission Spectra ◽  
Electrical Measurements ◽  
Cation Type ◽  
Edx Analyses ◽  
The Fourier Transform

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

Assessing the Power of Electron Back Scattering Diffraction Characterization of Deformed F-138 Steel from the View Point of Crystal Diffraction

2014 ◽  
Vol 51 (9) ◽  
pp. 634-655
Author(s):  
R. E. Bolmaro ◽  
M. C. Avalos ◽  
N. S. De Vincentis ◽  
A. M. Kliauga ◽  
H.-G. Brokmeier
Keyword(s):  
View Point ◽  
Back Scattering

APPLICATION OF ACOUSTIC METHODS IN RESEARCHES OF THE BOTTOM SEDIMENT DYNAMICS

2018 ◽  
Author(s):  
Б. Дивинский ◽  
B. Divinskiy ◽  
И. Грюне ◽  
I. Gryune ◽  
Р. Косьян ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Sediment Concentration ◽  
Irregular Waves ◽  
Single Frequency ◽  
Contactless Measurement ◽  
Measurement Means ◽  
Uniform Field ◽  
Wave Flume ◽  
Acoustic Methods ◽  
Back Scattering

Acoustic methods belong to contactless measurement means, possess high spatial and time resolution. Thus, the use of multifrequency allows directly profile both concentration and granulometric structure of the suspended substances. In 2008 in the Big Wave Flume (Hanover, Germany) by efforts of the Russian and German scientists there have been carried out the experiment on studying the bottom material suspension laws under the influence of irregular waves. The Aquascat 1000 acoustic back scattering sensor (ABS) manufactured by British company Aquatec (www.aquatecsubsea.com), equipped by a three-frequency transmitter with frequencies 1,0, 2,0 and 3,84 MHz, has been set on distance of 0,75 m from the bottom and 111 m from wave generator at the total depth of 3,2 m. Several dozen series of measurements at various parameters of surface waves have been carried out. The general picture of suspension is so that the external dynamic influence (currents, wave movements, turbulence, gravitation forces) creates a non-uniform field (gradient) of the suspended particles and in most cases due to this the average size of particles undergoes to the spatial-time variations. For this reason while defining the mass concentration of suspended sediment, using the single frequency transmitter there is necessity for numerous definition of the suspension granulometric structure what by isn’t always possible. If two and more frequencies are used the observed results comparison can give the information on average diameters of particles and on that basis the calculation of suspended sediment concentration is possibleLet's emphasize the basic advantages of back scattering acoustic gauges usage: – Obtaining the particles sizes and concentration distribution profiles is possible; – The initial granulometric structure of bottom sediments can be unknown (at use of several frequencies). The following can be referred to some lacks of the device: – The system should be calibrated in laboratory conditions; – In a positive feedback conditions the iterative computing process can converge to zero or to infinity. In this case experiments with a variation of carrier frequencies chosen for the analysis allow partially solve the problem (say experiments with different frequencies pairs, as 2/1 of MHz or 4/2 MHz).

A UHF Compact Complex Impedance-transforming Balun with High Isolation

2020 ◽  
Vol 13 (8) ◽  
pp. 1135-1144
Author(s):  
Kittipong Nithiporndecha ◽  
Chatrpol Pakasiri
Keyword(s):  
Complex Impedance ◽  
Output Port ◽  
Reflection Coefficients ◽  
Coupled Line ◽  
High Isolation ◽  
Line Structure ◽  
Source Impedance ◽  
Phase Balance ◽  
High Output

Background: A compact complex impedance-transforming balun for UHF frequencies, which is based on a coupled-line structure that matched all ports and provided high output port isolation, was designed in this paper. Methods: A lumped component transformation was used to minimize circuit size. The implemented circuit operated at 433 MHz with the reflection coefficients less than -16 dB at all ports, 0.22 dB amplitude balance and 180° phase balance at the output ports. The signal coupling between the output ports was -16.8 dB. The circuit size is small at 0.032λ. Results: Complex impedance-transforming baluns were designed to operate at 433 MHz. The source impedance at port 1 was set at Zs = 12 - j12Ω and the load impedances at port 2 and 3 were set at ZL = 80 + j30Ω. Conclusion: A compact complex impedance-transforming balun at UHF frequency, with all ports matched and high isolations, was designed and illustrated in this paper.

Color Etching for Characterization the Grain Orientation in Spheroidal Graphite Cast Iron

2007 ◽  
Vol 537-538 ◽  
pp. 389-396 ◽  
Author(s):  
Ibolya Kardos ◽  
Zoltán Gácsi ◽  
Péter János Szabó
Keyword(s):  
Cast Iron ◽  
Crystallographic Orientation ◽  
Grain Orientation ◽  
Test Material ◽  
Spheroidal Graphite ◽  
Metallic Materials ◽  
Additional Information ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Back Scattering

Color etching is a widely used technique for visualizing different phases in metallic materials. Its advantage to the traditional etching techniques is that it gives additional information within one phase, namely, the color shade of a given phase can change in a certain range. This paper demonstrates that, due to the physics of the color etching, the shade of a phase also depends on the crystallographic orientation of the investigated grain. As a test material, spheroidal graphite cast iron was used, and individual grain orientation was identified by automated electron back scattering diffraction (EBSD). Results showed that there is a strong correlation between grain orientation and the shades obtained by color etching.

Primary involvement of K+ conductance in membrane resonance of trigeminal root ganglion neurons

1988 ◽  
Vol 59 (1) ◽  
pp. 77-89 ◽  
Author(s):  
E. Puil ◽  
B. Gimbarzevsky ◽  
I. Spigelman
Keyword(s):  
Electrical Properties ◽  
Channel Blocker ◽  
Complex Impedance ◽  
Membrane Potentials ◽  
K Channel ◽  
Bathing Medium ◽  
Trigeminal Root ◽  
Membrane Resonance ◽  
Ganglion Neurons ◽  
Impedance Magnitude

1. The complex impedances and impedance magnitude functions were obtained from neurons in in vitro slices of trigeminal root ganglia using frequency-domain analyses of intracellularly recorded voltage responses to specified oscillatory input currents. A neuronal model derived from linearized Hodgkin-Huxley-like equations was used to fit the complex impedance data. This procedure yielded estimates for membrane electrical properties. 2. Membrane resonance was observed in the impedance magnitude functions of all investigated neurons at their initial resting membrane potentials and was similar to that reported previously for trigeminal root ganglion neurons in vivo. Tetrodotoxin (10(-6) M), a Na+-channel blocker, applied in the bathing medium for 20 min produced only minor changes, if any, in the resonance, although gross impairment of Na+-spike electrogenesis was apparent in most of the neurons. Brief applications (1-5 min) of a K+-channel blocker, tetraethylammonium (TEA; 10(-2) M), increased the impedance magnitude and abolished, in a reversible manner, the resonant behavior. In all cases, the resonant frequency was decreased by TEA administration prior to total blockade of resonance. 3. The TEA-induced blockade of resonance was associated with decreases in the estimates of the membrane conductances, without significant alterations of input capacitance. A particularly large decrease was observed in Gr, the time-invariant resting conductance that includes a lumped leak conductance component. The voltage- and time-dependent conductance, GL, and associated relaxation time constant, tau u, also declined progressively during administration of TEA. 4. Systematic variations in the membrane potentials of trigeminal root ganglion neurons were produced by intracellular injections of long-lasting step currents with superposition of the oscillatory current stimuli, in order to assess the effects of TEA on the relationship of the electrical properties to the membrane potential. Applications of TEA led to a depolarizing shift in the dependence of the membrane property estimates, suggesting voltage-dependence of the effects of TEA on presumed K+ channels in the membrane. 5. These data suggest a primary involvement of K+ conductance in the genesis of membrane resonance. This electrical behavior or its ionic mechanism is a major modulator of the subthreshold electrical responsiveness of trigeminal root ganglion neurons.

Studies of inhomogeneous substances by ultrasonic back-scattering

1976 ◽  
Vol 2 (3) ◽  
pp. 195-198 ◽  
Author(s):  
B. Fay ◽  
K. Brendel ◽  
G. Ludwig
Keyword(s):  
Back Scattering

scholarly journals Near-Field Scanning Millimeter-Wave Microscope Operating Inside a Scanning Electron Microscope: Towards Quantitative Electrical Nanocharacterization

2021 ◽  
Vol 11 (6) ◽  
pp. 2788
Author(s):  
Petr Polovodov ◽  
Didier Théron ◽  
Clément Lenoir ◽  
Dominique Deresmes ◽  
Sophie Eliet ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Millimeter Wave ◽  
Radiation Effects ◽  
Near Field ◽  
Complex Impedance ◽  
Standard Operating Procedure ◽  
Critical Issue ◽  
Transverse Electromagnetic ◽  
Scanning Electron

The main objectives of this work are the development of fundamental extensions to existing scanning microwave microscopy (SMM) technology to achieve quantitative complex impedance measurements at the nanoscale. We developed a SMM operating up to 67 GHz inside a scanning electron microscope, providing unique advantages to tackle issues commonly found in open-air SMMs. Operating in the millimeter-wave frequency range induces high collimation of the evanescent electrical fields in the vicinity of the probe apex, resulting in high spatial resolution and enhanced sensitivity. Operating in a vacuum allows for eliminating the water meniscus on the tip apex, which remains a critical issue to address modeling and quantitative analysis at the nanoscale. In addition, a microstrip probing structure was developed to ensure a transverse electromagnetic mode as close as possible to the tip apex, drastically reducing radiation effects and parasitic apex-to-ground capacitances with available SMM probes. As a demonstration, we describe a standard operating procedure for instrumentation configuration, measurements and data analysis. Measurement performance is exemplarily shown on a staircase microcapacitor sample at 30 GHz.

Thickness measurements by using back-scattering of gamma photons

2021 ◽  
Author(s):  
Rohit ◽  
Inderjeet Singh ◽  
B. Singh ◽  
B. S. Sandhu ◽  
A. D. Sabharwal
Keyword(s):  
Back Scattering ◽  
Thickness Measurements
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